GB2182875A - The reinforcement of pistons of aluminium or aluminium alloy - Google Patents
The reinforcement of pistons of aluminium or aluminium alloy Download PDFInfo
- Publication number
- GB2182875A GB2182875A GB08624820A GB8624820A GB2182875A GB 2182875 A GB2182875 A GB 2182875A GB 08624820 A GB08624820 A GB 08624820A GB 8624820 A GB8624820 A GB 8624820A GB 2182875 A GB2182875 A GB 2182875A
- Authority
- GB
- United Kingdom
- Prior art keywords
- reinforcement
- aluminium
- crown
- piston
- aluminium alloy
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000002787 reinforcement Effects 0.000 title claims abstract description 59
- 239000004411 aluminium Substances 0.000 title claims abstract description 35
- 229910052782 aluminium Inorganic materials 0.000 title claims abstract description 35
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 title claims abstract description 35
- 229910000838 Al alloy Inorganic materials 0.000 title claims abstract description 24
- 238000002485 combustion reaction Methods 0.000 claims abstract description 39
- 238000000034 method Methods 0.000 claims description 16
- 229910010293 ceramic material Inorganic materials 0.000 claims description 7
- 239000000463 material Substances 0.000 claims description 5
- 238000005266 casting Methods 0.000 claims description 4
- 230000003014 reinforcing effect Effects 0.000 claims description 4
- 238000007711 solidification Methods 0.000 claims description 4
- 230000008023 solidification Effects 0.000 claims description 4
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims description 2
- 229910052749 magnesium Inorganic materials 0.000 claims description 2
- 239000011777 magnesium Substances 0.000 claims description 2
- 229910052581 Si3N4 Inorganic materials 0.000 claims 1
- 239000011810 insulating material Substances 0.000 claims 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 claims 1
- 239000007787 solid Substances 0.000 claims 1
- 229910052751 metal Inorganic materials 0.000 abstract description 5
- 239000002184 metal Substances 0.000 abstract description 5
- 238000009716 squeeze casting Methods 0.000 abstract description 3
- 229910000831 Steel Inorganic materials 0.000 description 4
- 229910045601 alloy Inorganic materials 0.000 description 4
- 239000000956 alloy Substances 0.000 description 4
- 239000010959 steel Substances 0.000 description 4
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 229910002077 partially stabilized zirconia Inorganic materials 0.000 description 2
- 239000012779 reinforcing material Substances 0.000 description 2
- 229910001208 Crucible steel Inorganic materials 0.000 description 1
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 1
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D19/00—Casting in, on, or around objects which form part of the product
- B22D19/0009—Cylinders, pistons
- B22D19/0027—Cylinders, pistons pistons
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D15/00—Casting using a mould or core of which a part significant to the process is of high thermal conductivity, e.g. chill casting; Moulds or accessories specially adapted therefor
- B22D15/02—Casting using a mould or core of which a part significant to the process is of high thermal conductivity, e.g. chill casting; Moulds or accessories specially adapted therefor of cylinders, pistons, bearing shells or like thin-walled objects
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
- F02F3/00—Pistons
- F02F3/10—Pistons having surface coverings
- F02F3/12—Pistons having surface coverings on piston heads
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
- F02F7/00—Casings, e.g. crankcases
- F02F7/0085—Materials for constructing engines or their parts
- F02F7/0087—Ceramic materials
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B3/00—Engines characterised by air compression and subsequent fuel addition
- F02B3/06—Engines characterised by air compression and subsequent fuel addition with compression ignition
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05C—INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES
- F05C2201/00—Metals
- F05C2201/02—Light metals
- F05C2201/021—Aluminium
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05C—INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES
- F05C2201/00—Metals
- F05C2201/04—Heavy metals
- F05C2201/0433—Iron group; Ferrous alloys, e.g. steel
- F05C2201/0448—Steel
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- General Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Pistons, Piston Rings, And Cylinders (AREA)
Abstract
A reinforcement 31 for the crown of a piston of aluminium or aluminium alloy for an internal combustion engine is provided with re-entrant forming legs 35 and annular groove 39. The reinforcement is placed in a crown-forming part of a piston die in a squeeze casting apparatus and the piston is squeeze cast. The molten metal enters the re-entrants and these are so shaped that when the molten metal has solidified, keys are formed which securely connect the reinforcement to the aluminium or aluminium alloy. Further reinforcements can then be readily brazed or welded to the reinforcement member. <IMAGE>
Description
SPECIFICATION
The reinforcement of pistons of aluminium or aluminium alloy
The invention relates to the reinforcement of pistons of aluminium or aluminium alloy and in particularto the reinforcement of crowns of such pistons.
Because oftheircomparatively lightweight, aluminium and aluminium alloys are commonly used in the manufacture of pistons for internal combustion engines. They suffer, however, from the disadvantages that, as compared with many other metal materials, such as ferrous materials, they do not wearwell and are not well able to withstand elevated temperatures. The most arduous conditions encountered by an internal combustion engine piston are at the crown end of the piston which, in use, bounds the combustion chamber, since it is in the combustion chamber that the highesttemperatures are found.
Accordingly, there have been various proposals for reinforcing crowns of aluminium or aluminium alloy pistons to render them better able to withstand these conditions. In all such cases, however, there has been the problem of connecting the reinforcing materials securely to the aluminium or aluminium alloy because aluminium does not readily bond to
many reinforcing materials and a strong bond is essential, since any failure ofthe connection can have far reaching consequences.
According to a first aspect ofthe invention, there is
provided a method of reinforcing the crown of a
piston ofaluminium or aluminium alloyforan internal combustion engine, the method comprising
inserting a crown reinforcement member into a crown-forming part of a piston die, filling the die with molten aluminium or aluminium alloy and then solidifying the molten aluminium oraluminium alloy under pressu te, the reinforcement defining a combustion bowl forthe piston and including an annular groove extending around a combustion chamber-forming portion ofthe reinforcement into which the molten aluminium or aluminium alloy flows during casting to form, on solidification, a key
holding the reinforcement in position.
According to a second aspectofthe invention, there is provided a piston for an internal combustion
engine comprising a body of aluminium or
aluminium alloy and a reinforcement defining a
combustion bowl forthe piston and including an annular groove extending around a combustion chamber-forming portion ofthe reinforcement into which the aluminium or aluminium alloyextendsto form a key holding the reinforcement in position.
The following is a more detailed description of
some embodiments of the invention, by way of
example, reference being made to the
accompanying drawings in which:
Figure lisa cross-section of a third form of
reinforcement connected to a crown of a piston for an internal combustion engine,
Figure2 is a cross-section of a fourth form of
reinforcement connected to a piston for an internal combustion engine, and
Figure 3 is a cross-section of a fifth form of reinforcement connected to a piston for an internal combustion engine.
Referring first to Figure 1, a piston comprises a body portion 30 of aluminium or aluminium alloy and has connected thereto a reinforcement 31.
The reinforcement 31 is formed from a precision cast steel and comprises a central combustion bowl 32 and an outer portion 33 having a flange 34 depending from its periphery. A plurality of legs 35 depend from the undersurface ofthe plate and terminate in increased diameter portions 35a, so forming a re-entrant 36 between each increased diameter portion 1 5a and the associated leg 35. As shown, the legs 35 depend from the undersurface of the outer portion 33 and from the undersurface ofthe combustion bowl 32. The cross-section of the legs 35 is as small as practicable to minimise the heat transfer downwardly from the legs and into the aluminium or aluminium alloy.
The lower edge of the flange 34 is provided with an annular inwardly directed lip 37 soforming afurther re-entrant 18 extending around the reinforcement between the flange 14 and the outer portion 33.
Afurther re-entrant 39 is provided by a groove formed during the casting ofthe reinforcement 31 and extending around the undersurface of the combustion bowl 32.
The undersurface ofthe reinforcement 31 is covered with a layer 40 of ceramic material which may be applied by a spray coating process or any other suitable process. Suitable ceramic materials are silicon-nitrides, or zirconium based ceramics or itria or magnesium based ceramics. For example, partially stabilized zirconia or magnesia partially stabilized zirconia may be used. The coating is arranged so that the legs are not covered. The purpose ofthe coating 40 isto provide a heat-insulating barrier between the reinforcement 31 and the piston body 30.
The reinforcement 31 is incorporated into the piston inthefollowing way.
The reinforcement 31 is placed in a crown-defining part of a lower die member of a crown-down piston squeeze casting apparatus. Accordingly, the undersurface of the reinforcement 31 faces upwardly.
The lower die member is then filled with molten aluminium oraluminium alloy and an upper die member is lowered to close the die and then apply a load of several tons to the molten metal while it is solidifying. This removesvoids inthe metal and causes the metal to flow into all the re-entrants 36, 38,39 provided on the undersurface of the reinforcement 31. After solidification has been completed, the upper die is removed and the cast piston is removed from the die.
As will be seen in Figure 1,thesolidified aluminium or aluminium alloy in the re-entrants 36 around the legs, the re-entrant 38 around the flange and the re-entrant 39 around the combustion bowl 32 provide mechanical interlocks between the reinforcements 31 and the aluminium alloy holding these two parts together.
Accordingly, a piston is produced in which the crown and the combustion bowl 32 formed therein are formed of steel which is better able to withstand the high temperatures encountered in operation, particularlywherethe engine is a diesel engine. The reinforcement 31 and the piston body 30 arse firmly interlocked to prevent any possibilityofthe reinforcement 31 becoming detached in operation.
Referring nextto Figure 2, parts common to Figure 1 and to Figure 2 will be given the same reference numerals and will not be described in detail. In this embodiment, the legs 35 on the reinforcement 31 are omitted. The reinforcement 31 is otherwise the same as is connected to the aluminium or aluminium alloy as described above with reference to FigureS. The flowofthealuminium oraluminiumalloyintothe re-entrant 38 between the flange 34 and the outer portion 33 of the reinforcement 31 and into the groove 39 around the combustion bowl 32 provides a mechanical interlock which has been found sufficientto hold the reinforcement 31 firmly in position on the aluminium oraluminium alloy body 30.
Referring nextto Figure3, partscommonto
Figures 1 and to Figure 3will be given the same reference numerals and will not be described in detail.
In this embodiment, the reinforcement 31 is not provided with any legs 35 and the groove 39 on the undersurface of the combustion bowl 32 is omitted.
Instead, the undersurface ofthe combustion bowl 32 is provided with a number of outwardly spaced projections 41. A steel cap 42 is press fitted overthe undersurface ofthe combustion bowl 32 so that the inner surface of the cap 42 engages the projections 41 to space the cap 42 from the combustion chamber undersurface. In this way, a closed insulating chamber 43 is formed between the cap 42 and the combustion chamber 32. The cap 42 is provided with a circumferential re-entrant groove 44.
The outer surface of the outer portion 33 ofthe reinforcement 31 has a coating 45 of a ceramic material which may be any ofthe materials described above with reference to Figure 1 and be applied to any ofthetechniques described above with reference to Figure 1.
The reinforcement of Figure 3 is incorporated by squeeze casting in the manner described above with reference to Figure 1. The aluminium or aluminium alloyforms an interlock with the re-entrant 38 between the flange 34 and the outer portion 33 and the groove 44 ofthe steel cap 42. In this way, the reinforcement 31 is connected firmly to the piston body 30.
The closed chamber 43 provides an insulating air gap between the combustion bowl 32 and the aluminium or aluminium alloy body30 and so reduces the transfer of heatfrom the combustion bowl32tothealuminiumoraluminium alloy body 30.
It will be appreciated that, in any of the embodiments described above with reference to
Figures 1 to 3 of the drawings, the number and position of the re-entrants provided can be varied as required. For example, only the legs 35 need be provided, oronlythe re-entrant 36 between the flange 34 and the outer portion 33 or only the groove 39 or 44 on the undersurface of the combustion bowl 32 orthecap42 oranycombination ofthese re-entrants. It is not essential that the reinforcement forms a combustion bowl, it may be a disc ofsteel.
The reinforcement need not be made of steel; it can be made of any material better able than the aluminium or aluminium alloy to withstand the conditions encountered in the combustion chambers of internal combustion engines.
Claims (14)
1. A method of reinforcing the crown of a piston of aluminium or aluminium alloyforan internal combustion engine, the method comprising inserting a crown reinforcement member into a crown-forming part of a piston die, filling the diewith molten aluminium oraluminium alloyandthen solidifying the molten aluminium or aluminium alloy under pressure, the reinforcement defining a combustion bowl forthe piston and including an annular groove extending around a combustion chamber-forming portion of the reinforcement into which the molten aluminium or aluminium alloy flows during casting to form, on solidification, a key holding the reinforcement in position.
2. A method according to claim 1, wherein the reinforcement includes one or more legs, each depending from the reinforcement and having an increased diameter end portion to form, with the associated leg, a re-entrant portion which interlocks with the solid aluminium or aluminium alloy.
3. A method according to claim 1 orclaim2, wherein the groove is formed directly on the undersurface ofthe combustion chamber-forming portion ofthe reinforcement.
4. A method according to any one of claims 1 to 3, and further comprising, afterthe connection of the reinforcementtothealuminium oraluminiumalloy, the step of connecting a further crown part to the reinforcement.
5. A method according to claim 4, wherein the further crown partforms a crown end surface and an insulating chamber between the reinforcement and said crown end surface.
6. A method according to claim 5, wherein the insulating chamber isfilled with heat-insulating material or is evacuated.
7. A method according to any one of claims 1 to 6, wherein the reinforcement includes an annular outer portion having a flange depending therefrom to form an outer edge ofthe crown, there being an annular re-entrant portion formed between the flange and the outer portion into which the molten aluminium or aluminium alloy flows during casting to form, on solidification, a key holding the reinforcement in position.
8. A method according to any one of claims 1 to 7, wherein the undersurface of the reinforcement is covered with a ceramic material.
9. A method according to any one of claims 1 to 8, wherein at least a portion of the upper surface of the reinforcement is covered with a ceramic material.
10. Amethod according to claim 8 or claim 9, wherein the ceramic material is sprayed onto the reinforcement.
11. A method according to claim 10,whereinthe ceramic material is silicon-nitride orazirconium based material ora magnesium based material.
12. A method of reinforcing a crown of a piston substantially as hereinbefore described with reference to the accompanying drawings.
13. A piston for an internal combustion engine comprising a body of aluminium or aluminium alloy and a reinforcement defining a combustion bowl for the piston and including an annular groove extending around a combustion chamber-forming portion ofthe reinforcement into which the aluminium or aluminium alloy extends to form a key holding the reinforcement in position.
14. A piston for an internal combustion engine substantially as herein before described with reference to the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08624820A GB2182875B (en) | 1983-02-04 | 1986-10-16 | The reinforcement of pistons of aluminium or aluminium alloy |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB838303108A GB8303108D0 (en) | 1983-02-04 | 1983-02-04 | Reinforcement of pistons |
| GB838328116A GB8328116D0 (en) | 1983-10-20 | 1983-10-20 | Reinforcement of pistons |
| GB08624820A GB2182875B (en) | 1983-02-04 | 1986-10-16 | The reinforcement of pistons of aluminium or aluminium alloy |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB8624820D0 GB8624820D0 (en) | 1986-11-19 |
| GB2182875A true GB2182875A (en) | 1987-05-28 |
| GB2182875B GB2182875B (en) | 1987-11-04 |
Family
ID=27261954
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08624820A Expired GB2182875B (en) | 1983-02-04 | 1986-10-16 | The reinforcement of pistons of aluminium or aluminium alloy |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2182875B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5238046A (en) * | 1990-09-20 | 1993-08-24 | Magotteaux International | Method of manufacturing a bimetal casting and wearing part produced by this method |
| EP2540417A4 (en) * | 2010-02-25 | 2014-01-01 | Toyota Motor Co Ltd | METHOD FOR MANUFACTURING HOLLOW BONDED OBJECT, AND METHOD FOR MANUFACTURING PISTON FOR INTERNAL COMBUSTION ENGINE |
-
1986
- 1986-10-16 GB GB08624820A patent/GB2182875B/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5238046A (en) * | 1990-09-20 | 1993-08-24 | Magotteaux International | Method of manufacturing a bimetal casting and wearing part produced by this method |
| EP2540417A4 (en) * | 2010-02-25 | 2014-01-01 | Toyota Motor Co Ltd | METHOD FOR MANUFACTURING HOLLOW BONDED OBJECT, AND METHOD FOR MANUFACTURING PISTON FOR INTERNAL COMBUSTION ENGINE |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8624820D0 (en) | 1986-11-19 |
| GB2182875B (en) | 1987-11-04 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |